Use multiple displays with your Mac
You may be able to connect more than one display to your Mac. To do so, you need a video cable for each display, and you might need an adapter. See the Apple Support article Adapters for the Thunderbolt 3 or USB-C port on your Mac or iPad Pro.
After you connect the displays to your Mac, you can choose whether to use them as an extended desktop or for video mirroring.
Connect the displays
For each display, securely connect a video cable (and adapter, if necessary) from a video output port on your Mac to the video input port on the display. See About the video ports on Mac.
You can connect one or more external displays, depending on your Mac.
For Mac computers with Apple silicon: You can connect a single external display to your Mac. Docks don’t increase the number of displays you can connect. On a Mac mini with an Apple M1 chip, you can connect a second display to the HDMI port. See the Apple Support article Mac computers with Apple silicon.
For Mac computers with Thunderbolt 3 (USB-C): You can connect a single display to each port. If you connect multiple Thunderbolt devices to each other, the Thunderbolt 3 display must be the last device in the chain. If your Thunderbolt 3 display has USB ports, those can be used for data and power.
For Mac computers with Mini DisplayPort, Thunderbolt or Thunderbolt 2: You can connect up to two displays. If the displays themselves have Thunderbolt ports, you can connect one display to another, and then connect one of the displays to a Thunderbolt port on your Mac. If your Mac has two Thunderbolt ports, you can connect each display to separate Thunderbolt ports on your Mac. A DisplayPort device must be the last device in a chain of connected Thunderbolt devices. See Connect a display, TV or projector to Mac.
Note: Only the device directly connected to your Mac receives power from the computer’s Thunderbolt port. The other devices in the chain must be powered by separate power adapters.
If your Mac doesn’t detect a connected display
On your Mac, choose Apple menu
Click the Detect Displays button. (You may need to press the Option key to see the Detect Displays button.)
You can also try putting your Mac to sleep and then waking it.
Set up the displays as an extended desktop
You can arrange your displays in any configuration to create an extended desktop. For example, you can set your displays side by side to create one large continuous desktop.
On your Mac, choose Apple menu
Follow the onscreen instructions.
Set up the displays for video mirroring
Video mirroring shows the entire desktop on each connected display.
On your Mac, choose Apple menu
Set both displays to the same resolution.
Click Arrangement, then select Mirror Displays.
Set up some displays for mirroring and others for an extended desktop
If more than two displays are connected to your Mac, you can specify that some displays use mirroring, showing the entire desktop, and other displays show the extended desktop (displaying the desktop across two or more displays). For example, if you have three displays, you can have two displays showing the same information and the third display showing the extended desktop.
Use the task above to set up all the displays as an extended desktop.
Press and hold the Option key and drag one display icon onto another display icon to mirror those two displays.
If you are playing a DVD on a television connected to your Mac, click the Arrangement button in Displays preferences and move the menu bar to the television. If you don’t see an Arrangement button, your Mac is only capable of mirroring.